Justification:
This species is very rare and restricted to West Kalimantan, and is only found in riverine areas. It is threatened by continued loss of habitat due to clearing of mangrove forests for commercial timber and oil palm plantations. There has been an estimated 29% decline in mangrove area within this species range since 1980. As this species is only found along riverine areas, the total extent of occurance is estimated to be less than 5,000 km² and is very fragmented. This species is listed as Endangered.

This species is found in the upstream estuarine zone in the high intertidal region (Robertson and Alongi 1992). It prefers freshwater and is only found in riverine areas. This species can grow to more than 25 m, but is a slow growing species that is found in single stands up to 70 km from the sea.

This species is threatened by extensive habitat loss from logging activities to create timber and palm oil plantations. Although local estimates are uncertain due to differing legislative definitions of what is a 'mangrove' and to the imprecision in determining mangrove area, current consensus estimates of mangrove loss in the last quarter-century report an approximately 29% decline in mangrove areas in countries within this species range since 1980 (FAO 2007).

All mangrove ecosystems occur within mean sea level and high tidal elevations, and have distinct species zonations that are controlled by the elevation of the substrate relative to mean sea level. This is because of associated variation in frequency of elevation, salinity and wave action (Duke et al. 1998). With rise in sea-level, the habitat requirements of each species will be disrupted, and species zones will suffer mortality at their present locations and re-establish at higher elevations in areas that were previously landward zones (Ellison 2005). If sea-level rise is a continued trend over this century, then there will be continued mortality and re-establishment of species zones. However, species that are easily dispersed and fast growing/fast producing will cope better than those which are slower growing and slower to reproduce.

In addition, mangrove area is declining globally due to a number of localized threats. The main threat is habitat destruction and removal of mangrove areas. Reasons for removal include cleared for shrimp farms, agriculture, fish ponds, rice production and salt pans, and for the development of urban and industrial areas, road construction, coconut plantations, ports, airports, and tourist resorts. Other threats include pollution from sewage effluents, solid wastes, siltation, oil, and agricultural and urban runoff. Climate change is also thought to be a threat, particularly at the edges of a species range. Natural threats include cyclones, hurricane and tsunamis.